Due to the electrification of the transportation sector, in the form of hybrid or fully electric vehicles, there is a rising need for battery charging stations for these vehicles. In such a charging station, a battery or accumulator that is used for supplying a drive of the vehicle with electrical power may be charged with electrical energy drawn from a large-scale power grid.
Known battery charging has been slow, ranging within a few hours. However, the development of new fast charging algorithms and of new power electronic converters makes it possible to charge a battery within about 20 minutes. However, such fast charging algorithms may degrade the efficiency of the charging due to high losses of the electric converters.
For enhancing the efficiency of universal battery charging, for example for e-mobility applications, modular converters have been proposed that include a plurality of charging modules, each of which generates a part of the charging current to be supplied to the battery.
In US 2004/0189251 A1 a master-slave configuration has been proposed for controlling the charging modules. The measurements of the battery voltage are led to a central (master) controller, where the battery charging information is also stored. The calculations of the current references for the modules are then done centrally, and the information about the reference value for the current of each individual module is communicated to local (slave) controllers that are responsible for the operation of each individual charging module.